1. Field of the Invention
The invention relates to a reinforcing component of which the basic material is austenitic cast iron and which is intermetallically bonded with an engine component made from an aluminum-based alloy, in particular a piston. Reinforcing components of this type are especially employed as ring carriers and in a few cases also as trough-edge protection in connection with aluminum pistons for Diesel engines.
The bond of the reinforcing component--which consists of austenitic grey cast iron alloy in most cases--with the material of the piston is produced by the Alfin-process, which is known in the state of the art since about 1950, by immersing the reinforcing component in an AlSi-melt before the piston material is poured around it, whereby an intermetallic layer develops on the surface of the reinforcing component.
2. The Prior Art
The stresses to which pistons are exposed in Diesel engines, which have continually increased in the past, have revealed the strength limits of alfin-bonds produced heretofore, so that a higher bonding strength is required.
Therefore, it was proposed in DE-OS 42 21 448 to employ austenitic cast iron with a globular or vermicular graphite configuration as reinforcing material, which improves the strength of the bond as compared to the usual grey cast iron alloy material with a lamellar graphite configuration.
The drawbacks of this solution include abandonment of a ring carrier material that has been successfully used for a long time, poorer workability, lower thermal conductivity and slightly poorer resistance to wear of the grey cast graphite material as compared to the grey cast iron alloy type. In addition, grey cast iron qraphite material is slightly more expensive than the grey cast iron alloy type.